Skylights are widely used in all types of building constructions; however, inherently the skylights proposed heretofore have been deficient primarily due to their poor thermal insulation characteristics whereby such skylights have resulted in substantial heat loss from within each building associated therewith during winter seasons and substantial heat gain during summer seasons. Another deficiency of many of the previously proposed skylights is that each of such skylights is comparatively heavy and requires that a supporting curb and adjoining roof structure associated therewith be considerably stronger, resulting in greater costs.